<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body>
        用户名：<input type="text" id="username">
        <p></p>
        <script type="text/javascript">
            const input = document.querySelector("input");
            const p = document.querySelector("p");

            function handle(data){
                input.style.border= "2px solid #red";
                input.style.color = "bluesky";
                p.innerHTML = data.msg;
            };

            input.onblur = function(){
                let username = input.value;
                
                const script = document.createElement("script");
                script.src = "http://127.0.0.1:9000/jsonp-server";
                document.body.appendChild(script);
            }


        
        </script>
    </body>
</html>